Machine tools are used for a variety of cutting, drilling, machining, sanding and polishing operations. Of the various machine tools, the drill press is regularly used for more different functions than any other machine tool in the workshop. It is used to drill and ream, and can also be used for sanding, shaping, grinding, tapping threads, turning and almost any other woodworking job except sawing.
For many of the above-described operations, it is necessary to clamp a work piece to a work piece support table to hold the work piece, typically a piece of wood, in a steady position as the operation is being carried out on the work piece. If a series of holes are being drilled in a single work piece, the user must generally unclamp the work piece and shift the work piece position prior to drilling the next hole. The unclamping and movement of the work piece is often time consuming, requiring extra care in order to accurately re-position the work piece and clamp it in position on the work piece support table.
In order to alleviate the problem of having to unclamp and re-position the work piece, some drill presses are provided with a head assembly (which typically includes a motor, a moveable spindle and quill, and a power transmission mechanism) having a horizontal column which is slidably mounted to the drill press stand. This type of mounting arrangement for the head assembly allows the head assembly to be moved relative to the work piece, eliminating the need to unclamp the work piece from the support table in some cases. Although this system provides greater versatility than drill presses with a fixed head assembly, it is still often necessary to unclamp and reposition the work piece in order to carry out additional drilling or other operations.
Other types of machine tools, such as milling or boring machines generally include an X-Y table which is mounted for linear movement in the X and Y directions. This allows for re-positioning a work piece without unclamping it from a support table. However, X-Y tables require precision machined and ground lead screws and machined ways for movement of the table. These types of X-Y tables are often very expensive and, as a practical matter, are not generally used on drill presses.
The present invention resulted from observation of the limitations with the prior art drill presses and efforts to solve them.